1. Field of the Invention
This invention relates generally to lens systems and, more particularly, to a lens system utilizing one or more low refractive index lens elements contained within a higher refractive index enveloping medium.
2. Description of the Prior Art
Various lens systems are known. Such lens systems generally employ one or more refractive elements formed from a material having a relatively high index of refraction, such as plastic or glass, contained in a medium, such as air, having a relatively low index of refraction. While such systems are satisfactory for many applications, the many air-to-glass interfaces introduce various losses. In addition, conventional lens systems that use air as the enveloping medium are not entirely suitable for certain high temperature applications, such as those encountered in projection systems that utilize one or more high intensity cathode ray tubes or liquid crystal displays that should be cooled.